nanopb: added option for malloc build

This is required by the criterion package, while preserving previous behavior for all others.

pkgs/development/libraries/nanopb/default.nix

@@ -6,6 +6,7 @@
 , python3
 , stdenv
 , buildPackages
+, mallocBuild ? false
 }:
 
 stdenv.mkDerivation rec {
@@ -27,7 +28,7 @@ stdenv.mkDerivation rec {
     "-DBUILD_SHARED_LIBS=ON" # generate $out/lib/libprotobuf-nanopb.so{.0,}
     "-DBUILD_STATIC_LIBS=ON" # generate $out/lib/libprotobuf-nanopb.a
     "-Dnanopb_PROTOC_PATH=${buildPackages.protobuf}/bin/protoc"
-  ];
+  ] ++ lib.optional mallocBuild "-DCMAKE_C_FLAGS=-DPB_ENABLE_MALLOC 1";
 
   postInstall = ''
     mkdir -p $out/share/nanopb/generator/proto

pkgs/top-level/all-packages.nix

@@ -20818,6 +20818,7 @@ with pkgs;
   flatbuffers = callPackage ../development/libraries/flatbuffers { };
 
   nanopb = callPackage ../development/libraries/nanopb { };
+  nanopbMalloc = callPackage ../development/libraries/nanopb { mallocBuild = true; };
 
   gnupth = callPackage ../development/libraries/pth { };
   pth = if stdenv.hostPlatform.isMusl then npth else gnupth;